Animals Wildlife 9 Illuminating Facts About Iguanas By Catie Leary Writer and Photographer Georgia State University Catie Leary writes and curates visual stories about science, animals, the arts, travel, and the natural world. our editorial process Catie Leary Updated September 17, 2020 Nadezda Murmakova / Shutterstock Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Unless you're a herpetologist or dedicated reptile enthusiast, you might not know much about iguanas. These docile creatures are laid-back, and their unassuming nature is often the root of many misconceptions. Although they may seem quite stoney on the surface (literally — they can be as still as rocks!), the truth is, iguanas are majestic, complex creatures. In addition to being some of the largest lizards in the Americas, iguanas are highly adaptive animals that are found in a variety of environments, including tropical forests, arid deserts and even in the water. If you're looking for a crash course on the wonderful world of iguanas, here a few fascinating facts about these amazing creatures. There are 35 different iguana species Photo: Frontpage/Shutterstock You might be familiar with the green iguana (Iguana iguana), which is by far the most common and widespread iguana species in the Americas. However, iguanas come in many shapes, colors and sizes. One of the most visually striking members of the Iguanidae family is the Grand Cayman iguana (pictured). Also known as the blue iguana, this exquisite creature is one of the few naturally blue-hued animals in the world. It's also the heaviest of all iguanas. While it once existed in great abundance on the island of Grand Cayman, the species numbers have been on a steady decline for the past couple centuries due to habitat loss and predation by domestic dogs and cats. They are currently listed as endangered on the IUCN Red List, and there are only a handful of individuals left in the wild. Iguanas love sunbathing Photo: photoiconix/Shutterstock Just like all reptiles, iguanas are cold-blooded and thrive in hot climates. That's why you'll often see them basking in the warm sunlight. Whenever the temperature drops below 40 degrees Fahrenheit, the lizards' muscles essentially become paralyzed and they fall into a state of hibernation. This doesn't happen often in the hot tropics of Central America, but in places like southern Florida, where they've been introduced by humans, an unseasonable winter cold snap can literally cause scores of these scaled critters to lose their grip on tree limbs and fall to the ground. While it's quite an alarming sight to witness, the tumble doesn't necessarily mean certain death. As the National Weather Service in Miami explains in the video above. Iguanas can hold their own in a fight Photo: Tatiana Liubarskaya/Shutterstock Iguanas use their tail for balance while climbing and maneuvering, but these long appendages serve yet another purpose — self-defense. When encountering a predator or other threat, the iguana will distract and bewilder its attacker by thrashing its tail. Sometimes the tail will break off and the creature is able to make a quick getaway. (Don't worry, the tail grows back later.) In the event that a predator tries to eat an iguana, its tail is equipped with spiky spinal combs that makes it a difficult meal to swallow. Fiji banded iguanas have chamelon-like skin Photo: Galina Savina /Shutterstock Depending on their mood, Fiji banded iguanas are capable of changing their skin color from green to various shades of blue, gray and black — and that's not all. "Banded iguana skin is so photosensitive that any part of the skin in shade is a completely different color of green than the skin in sunlight," according to the San Diego Zoo. Despite their beauty, Fiji banded iguanas are exceedingly rare. Because of habitat loss and predation by introduced species like mongoose and domestic cats, their numbers have been in steady decline for the past century. Today, this "national treasure" of Fiji is listed as endangered. Some iguanas are excellent swimmers Photo: Neil Burton/Shutterstock While many iguanas are content to lounge on dry land or cling to shady tree limbs, the marine iguana of the Galapagos Islands spends a great deal of time under the sea. As seen in this fascinating video below, the creature uses its excellent swimming skills to forage for red and green algae: Because the iguana is a cold-blooded reptile that requires warmth to survive, you might wonder if swimming in the chilly ocean would poses any problems. However, thanks to its dark coloration, the marine iguana has no trouble soaking up the sun's rays. Still, it only takes a few minutes before an iguana's muscles start seizing up from chill, which is why they limit their underwater adventures to around 10 minutes max. Iguanas have a third eye Photo: stuphipps/Shutterstock Also known as a parietal eye, this organ is used to alert iguanas (as well as other reptiles) of aerial threats. Unlike the lizard's other two eyes, the parietal eye is quite simple in its physiology and can only detect changes in lightness and darkness. But that's more than enough to evade predators. So where exactly is it? In this photo, the parietal eye is that little light-colored scale on the top of the lizard's head between the two eyes. Iguanas are social butterflies Photo: jtairat/Shutterstock On the surface, reptiles seem like intensely stoic, solitary individuals, but that couldn't be further from the truth. Reptiles like iguanas have complex social relationships, and it's common to observe instances of pair-bonding and kin recognition. As Scientific American explains, this manifests in several ways in the green iguana, including "play behavior, cooperation, social nesting, counting, sophisticated learning and problem-solving abilities, social learning and the care and protection of siblings." Iguanas are vegan Photo: GUDKOV ANDREY/Shutterstock While some wild specimens have been known to occasionally feast on insects, iguanas are at their healthiest when they consume an all-vegetarian diet. "No iguana, even a young one, should ever be fed meat, dog or cat food, insects or any other kind of animal protein," according to the Green Iguana Society. (The website is no longer functioning.) Of course, just because they're vegetarians doesn't mean they can eat just any plant. For example, vets strongly discourage iguana owners from feeding the creatures too much cabbage or kale as it can cause goiter. Lettuce is yet another vegetable that should only be given in small quantities due to its low nutritional value. Iguanas live a really long time Photo: SGr/Shutterstock People have a tendency to acquire iguanas without fully understanding their basic needs for a healthy life. This includes a warm environment (75 to 95 degrees Fahrenheit), access to UVB light, a properly sized habitat and a healthy diet of vegetables. Depending on the species, iguanas can live anywhere from four to 60 years. This potentially long lifespan is exactly why purchasing one of these creatures on a whim is a terrible idea. If you're interested in taking on an iguana as a pet, the IguanaPet site has an illuminating list of myths and misconceptions about proper iguana care that both current and prospective owners should read.